Generally, a speech recognition apparatus performs speech recognition by referring to words (vocabulary items) recorded in a speech recognition dictionary, and a large number of words must be recorded in the speech recognition dictionary to increase a speech recognition rate. Thus, some speech recognition apparatuses have a function of updating the speech recognition dictionary by enabling a user to add and record words into an existing speech recognition dictionary, and/or a function of preparing a speech recognition dictionary for user's personal use.
For example, there is a speech recognition apparatus that reads, when detecting the start of mail preparing processing during the creation of a speech recognition dictionary used for composing an e-mail message in response to a voice input, document data obtained by an application; analyzes the document data; extracts an unknown word not contained in the existing speech recognition dictionary; and creates a speech recognition dictionary including the unknown word extracted (see Patent Document 1, for example).
Furthermore, there is a speech recognition apparatus that stores, when creating/updating a speech recognition dictionary, a first analysis dictionary in which written forms and reading of popular vocabulary items are recorded into a first analysis dictionary storage section; stores a second analysis dictionary in which written forms and reading of special vocabulary items are recorded into a second analysis dictionary storage section; carries out morphological analysis using both the analysis dictionaries with a text analysis section; records in a corresponding table, when giving reading to an input morpheme by a reading providing section 2, pairs of vocabulary/reading of the second analysis dictionary and pairs of other candidates/reading candidates concerning recorded vocabulary in the second analysis dictionary; creates a speech recognition dictionary with a speech recognition dictionary creating section on a basis of the contents of the corresponding table; and creates the speech recognition dictionary on a basis of correspondence between the recognized vocabulary items and the phonemic written form and other phonemic written form candidates of the second analysis dictionary (see Patent Document 2, for example).
Patent Document 1: Japanese Patent Laid-Open No. 2004-233577 (pp. 3-9 and FIGS. 1-9).
Patent Document 2: Japanese Patent Laid-Open No. 2003-271183 (pp. 6-12 and FIGS. 1-7).
In the conventional speech recognition apparatus with the foregoing configuration, a target at the time of creating or updating the speech recognition dictionary is limited to such an application capable of transmitting and receiving document data, and the frequency of using words for the recognition can vary greatly depending on the externally connected devices connected to the speech recognition apparatus, and the words and vocabulary items can differ depending on the externally connected devices. Considering these factors, the conventional speech recognition apparatus has a problem of being unable to carry out the speech recognition efficiently for separate externally connected devices by only creating or updating the speech recognition dictionary for a single application (that is, for a single externally connected device).
In addition, since the conventional speech recognition apparatus records the words passing through the analysis into the single speech recognition dictionary, the time taken for searching the speech recognition dictionary increases with the number of words recorded. This offers a problem of not only hindering the efficient speech recognition, but also reducing the recognition rate because of an increase in similar words.
The present invention is implemented to solve the foregoing problems. Therefore it is an object of the present invention to provide a speech recognition apparatus capable of carrying out the speech recognition efficiently in accordance with the externally connected devices.